Collapsing tap



March 30, 1948. R. STRICKLAND 2,438,626

' COLLAPSING TAP Filed June '7, 1946 4 Shets-Sheet 2 H 1. a y W ("MW a y w w H i a. w

March 30, 1948. I

R. M. STRICKLAND COLLAPSING TAP Filed June 7, 1946 '4 Sheets-Sheet 3 March 30, 1948. R. M; STRICKLAND Filed June 7, 1946 M charm Khwweys Patented Mar. 30, 1948 KINETED STATES PATENT OFFICE COLLAPSING TAP Royce M. Strickland, New Haven, Conn., assignor to The Geometric Tool Company, New Haven, Conn, a corporation of Connecticut Application June 7, 1946, Serial No. 675,025

16 Claims. 1

The present invention relates to improvements in collapsing taps, i, e., thread-cutting devices which are adapted to form threads within cavities in objects, such as pipe fittings, etc., and which have a plurality of thread-cutting chasers projectable outwardly or settable for a thread-cutin-g operation, and which are also releasable or collapsible inwardly, to be disengaged from the threads just out.

One of the objects of the present invention is to provide a superior collapsing tap characterized by strength and durability in use.

Another object of the present invention is to provide a device of the type described which is characterized by ease of setting and collapsing of its chasers.

A further object of the present invention is to provide a collapsing tap having a superior construction andarrangement of parts whereby the chasers may be released for removal and replacement.

Still another object of the present invention is to provide a superior collapsing tap combining strength and wear-resistance with compactness.

With the above and other objects in View, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a view in side elevation of one form of collapsing tap embodying the present invention and shown as set in readiness to cut threads;

Fig, 2 is a View thereof in front elevation, but on a larger scale;

Fig. 3 is a View of the collapsing tap in rear elevation;

Fig. 4 is a broken central-longitudinal sectional View taken on the line 4-4 of Fig. 2;

Fig. 5 is a similar view but taken on the line 55 of Fig. 2;

Fig. 6 is a transverse sectional view taken on the line 6-6 of Fig. 4;

Fig. 7 is a similar view taken on the line 1--1 of Fig. 4;

Fig, 8 is a broken longitudinal sectional view taken on the line 88 of Fig. 3;

Fig. 9 is a perspective view of the couplingmember;

Fig. 10 is a similar view of the releasingplunger;

Fig. 11 is a similar view of the assembly comprising the operating-sleeve, chaser-retracting 2 plungers and latch-member, together with one of the latch-releasing balls;

Fig. 12 is a perspective view of the latch-member;

Fig. 13 is a broken longitudinal sectional view corresponding to Fig. 4, but showing the parts in the positions which they assume when the chasers are retracted to disengage them from the work just threaded; and

Fig. 14 is a broken detail sectional view corresponding to the upper portion of Fig. 8 but showing the releasing-plunger moved forwardly into its releasing position, and showing the operatingsleeve and the tripping-sleeve moved rearwardly into position to efiect the full release of the chasers, whereby the latter may be removed from the structure,

The particular collapsing tap chosen for illustration' in the accompanying drawings for purposes of making'clear a preferred form of the present invention, includes a body-member or chaser-carrying member generally designated by the reference character l5 and generally of cylindrical form. The said body-member includes a rearwardly-projecting shank It by means of which the collapsing tap is adapted to be mounted in the turret of a screw machine or other suitable support.

Adjacent its forward end, the body-member I5 is slightly enlarged to provide a head-portion l1 and terminates at its forward end in a nose-portion 18 of substantially the same diameter as the main portion of the body-member including its shank l6. Secured against the forward end of the nose-portion I8 is a cap I9 held in place by means of screws 20.

The forward portion of the body-member I5 is formed with a forwardly-opening axial guiderecess 2| of cylindrical form throughout the major portion of its length, and in which is adapted to reciprocate a chaser-operating plunger 22. At its forward end, the said chaser-operating plunger is formed with four (more or less) chaser-operating arms 23 which extend substantially radially and also in a direction parallel with the longitudinal axis of the plunger itself. Each of the arms 23 is formed on one of its side faces with a coupling-rib 24 which is forwardly and inwardly inclined, as is especially well shown in Fig. 5.

Engaging with the inclined outer edge of each of the chaser-operating arms 23, is the inclined inner end of one of four similar chasers 25, each of which is provided with an inclined couplingrib 26 slidably fitting beneath the coupling-rib 3 e 24 of its complemental chaser-operating arm 23. Each of the said chasers 25 is formed upon its outer edge wtih thread-cutting teeth 21 and is mounted for movement in a substantially-radial exterior form and terminating at its rear in a:

radially-extending annular flange 3G. Mounted in turn upon the exterior of the operating-sleeve 29 is a tripping-sleeve 3! having its forward portion sized interiorly to reciprocatewith a smooth sliding fit upon the periphery of the forward or. main portion of the operating-sleeve 29 and hav-' ing its rear end recessed to accommodate and slide upon the periphery of the annular flange 35 at the rear of the said operating-sleeve.

At the junction of the main portion of its in-- terior periphery with the enlargedrear portion thereof, the tripping-sleeve 31 is formed with a -rearwardly-facing stop-shoulder '32 which is adapted to engage with a stop-screw 33 (Fig. 8) mounted in the annular'fiange 3B of'the operating-sleeve 25 and extending ina direction. parallel with the longitudinal axis of the device. For.

the purpose of holding the stop-screw 33. in a given position of adjustment, a coaxial lockscrew 34 is also threaded into the flange 35 so as to [5 by means of two (more or less) chaser-rd tracting springs 45-54, each of which is mounted in one of two similar sockets l 555 formed in the operating-sleeve 2t. The said sockets ex tend in substantial parallelism with the longitudinal axis of the device and open through the forward face of the operating-sleeve, as is shown in Fig. 5. Each of the chaser-retracting springs it-Ml is seated at its rear end against the end wall of its oomplemental socket 45 and presses at its forward end against the front wall of the adjacent one of two corresponding cup shaped' plungers -d-ES- Each of the said plungers'is mounted for reciprocation in one of the sockets 45-55 andimpinges at its forward end against the rear face of the head-portion l of the bodymember l5, as-is indicated in Fig. 5.

The interior of the body-member i5 is formed in its forward portion with four longitudinal clearance-grooves 47 respectively registering with andadapted to receive the plate-like chaser-op cratingv arms 23 of the chaser-operating plunger Adjacent its rear end, the chaser-operating plunger 22 is formed with a transverse coupling- 7 V notch 48 which receives the inner end of a coupling-leg 59 projecting radially inwardly from .the central portion of a T- shaped' adjustable coupling-member 55; The. said coupling-leg extends longitudinal guide-recess 2|, and at its outer end impinge against the rear end of the said stopscrew, as is indicated in Fig. 8.

The tripping-sleeve 3i above referred to may be moved rearwardly relative to the. operatingsleeve 25 upon which it slides in several different ways such, for instance, as by a suitable stop or abutment extending into an annular groove 3211 'or by means of a pivotal lever-handle 35. In

the manner which will hereinafter appear, the lever-handle will serve the dual purpose of resetting the chasers 25, and of effecting their release for radial inward movement.

The lever-handle 35 above referred to extends substantially radially with respect to the tap structure and is pivoted intermediate its respective opposite ends upon a removable pivot-pin 35 carried by the tripping-sleeve 3| and extending across. a clearance-passage 3?. in the said tripping-sleeve. The inwardly-projecting portion of the lever-handle 35 extends through a longitudinal clearance-slot 38 formed in the opcrating-sleeve 29, as is shown in Figs. 4 and 13'.

The inner end of the lever-handle 35 is spherically contoured and extends and rocks in a socket' 39 formed in the portion of the body-member I5 lying Within the said operating-sleeve 2a. For the purpose of, limiting the tripping-sleeve 3! to movement in an axial direction, the inner periphery of the forward portion of the said tripping-sleeve is formed with a longitudinal keyway to into which extends a key 4| (Figs. l and 13) mounted in and extending beyond the outer peripheryof the operating-sleeve 29.

Theroperating-sleeve '29 is, in turn, limited to movement in an axial direction by means of a key 42 mounted in and projecting beyond the outer periphery of the body-member l5 and having sliding engagement with a longitudinal clearance-notch 53 (Fig. 5) formed in the forward portion of the said. operating-sleeve. v

The operating-sleeve 29 is yieldingly urged to move'rearwardly relative to the body-member through .a relatively-long longitudinalcl'earanceslot 51 formed in the body-member 55. At its inner end, the said clearance-slotintersects the intersects the periphery of the'said body-member.

' The coupling-leg 49' of the coupling-member 7 5!! also'projects throughthe clearance-slot 53 before referred to and in which the key eta-isomoves. The said clearance-slot 43- communicates at its inner end with the clearance-slot 5| in the body-member i5, and communicates at its outer end with a longitudinal passage 53 formed in the operating-sleeve 29. The said passage 53 extends completely through the operating-sleeve 29 from the front to the rear thereof, and is of cylindrical form to snugly receive the cylindrical end portions of the head or cross of theT-shaped coupling-member 50' before referred to, in the manner indicated in Fig. 5. j j

The T-shaped coupling-member 5B is held against axial movement relative to the operating-;

sleeve 29, by means of a front adjusting-screw 54 and a rear'adjusting-screw 55. The said adjusting-screws 5 5 and 55 arethreade'd respective ly into the front and rear portions of the operating-sleeve 29 at a point slightly circumferentially displaced with respect to the longitudinal passage 53 and respectively thrust against seats 56 and 51. The seats '55 and 5lla're formed in the coupling-member 50 and respectively faceiOrwardly and rearwardly, and when the adjusting- .screws 54 and 55 are respectively seated there against, the coupling-member 50 is clampedbetween the two said screws. In this manner, the said coupling-member is rigidly held so'as to normally form a rigid feature of the-operating-sleeve 29, to thus transmit the movement of the latter to the chaser-operating plunger 22 within the bodymember I5. 1 V

For the purpose of releasably holdingthe: operating-sleeve 29 in its forward position against the tension of the chaser-retracting springs li t-44, a plate-like latch-member 58' is employed. The said. latch-member is mounted for movement toward and away from the central longitudinal axis of the structure in a transverse guide-groove 8 69 formed in the forward portion of the flange 30 at the rear of the operating-sleeve 29.

Theouter portion of the latch-member 56 is curved to substantially conform to the curvature of the outer periphery of the flange 30 at the rear of the operating-sleeve 29 while its inner edge is substantially straight save for its central portion, which is curved to substantially conform to the exterior periphery of the adjacent portion of the body-member l5. The central portion of the inner edge of the latch-member 58 is adapted to project into a transverse latching-groove 66 formed in the body-member l at a point substantially-diametrically-opposite the socket 39 in which the hand-lever 35 engages. The rear wall of the latching-groove 60 just referred to, constitutes a forwardly-facing latching-abutment 6! which is adapted to be engaged by the central portion of the rear face of the latch-member 68.

The latch-member 56 above referred to, is yieldingly urged inwardly to engage the central inner portion of its rear face with the latchingabutment 6!, by means of two helical latchsprings 62-62 fitting into suitable sockets in the said latch-member, as is shown in Fig. 7, the said latch-springs respectively having ball-bearings 63-63 interposed between their outer ends and the inner periphery of the rear portion of the tripping-sleeve 3 I, as shown in Fig. 7.

For the purpose of forcing the latch-member 58 outwardly to disengage its central portion from the latching-abutment 6|, the said latch-member is formed adjacent the respective opposite ends of its inner edge with forwardly-and-outwardlyinclined surfaces 64-64 on which respectively rest latch-releasing balls 66-65. The latch-releasing balls 65-65 just referred to are respectively mounted for movement in a direction parallel with the longitudinal axis of the device, in rearwardly-opening cylindrical sockets 66-66 formed in the rear portion of the operatingsleeve 29 and mainly in its annular flange 36.

The rear ends of the sockets 66-66 are suitably plugged to exclude dirt, while the forward portions of. each of the sockets break through the forward face of the annular flange 36. By this arrangement, the latch-releasing ball 65 in a given socket may assume a position in which it may be engaged by the rearwardly-facing stop-shoulder 32 within the rear portion of the tripping-sleeve 3|. Thus, in addition to serving as a stop-shoulder as before described, the surface 32 will also serve in a manner as will hereinafter appear, as a tripping-shoulder to force the latch-releasing balls 65-65 rearwardly in their respective sockets 66-66. When so moved, the said balls will ride against the inclined surfaces 64-64 of the said latch-member and thus force the latter radially outwardly to disengage the central inner portion of its rear face from the latchin-abutment 6| of the body-member l5.

For the purpose of normally limiting the rearward travel of the operating-sleeve 29 under the urge of the chaser-retracting springs 44, a stopball or stop-member 61 is employed, as is indicated in Figs. 8 and 14. The said stop-ball is mounted for movement in a radial direction in a closely-fitting radial clearance-passage 68 formed in the operating-sleeve 29, and at its inner end intersecting the inner periphery of the said opcrating-sleeve and at its outer end intersecting a longitudinal passage 69 also formed in the said operating-sleeve 29. Mounted for reciprocation in the passage 69 just referred to, is a releasingplunger 16 which normally projects beyond the rear face of the operating-sleeve 29. The said releasing-plunger is mainly of cylindrical form in cross section and is formed in its inner face with a longitudinal groove 1| in whichthe stopball 61 is adapted to ride, and with a clearancepocket 12 adapted under certain conditions to accommodate a part of the said stop-ball 61.

The releasing-plunger 10 above described, is normally yieldingly urged rearwardly to engage the curved forward wall of its longitudinal groove 1| with the stop-ball 61, by means of a helical spring 13 located in the forward portion of the longitudinal passage 69 in the operating-sleeve 29. The rear end of the said spring 13 thrusts rearwardly against the adjacent end of the releasing-plunger 19, while its forward end engages with the rear face of a spring-seat 14 mounted in the forward portion of the longitudinal passage 69. The said spring-seat is cut away on the forward portion of one side to provide it with a forwardly-facing stop-shoulder 15, The said stop-shoulder is engaged with the rear face of the head 16 of a stop-screw having a shank 11 threaded into the forward portion of the operatingsleeve 29. The head 16 of the said stop-screw is mainly seated in a forwardly-openmg recess 18 formed in the forward face of the operatingsleeve 29 and partly projects into an arcuate recess 19 formed in the forward inner corner of the tripping-sleeve 3|. The recess 19 is concentric with the recess 18, as is apparent from Fig. 2. As thus constructed and arranged, the rear face of the head 16 of the stop-screw serves to limit the forward movement of both the spring-seat 16 and the tripping-sleeve 3| with respect to the operating-sleeve 29.

The inner portion of the stop-ball 61 above referred to, normally projects into a longitudinal groove 86 formed in the periphery of the bodymember l5 and having its curved rear wall engaged by the stop-ball 61 to normally (but releasably) limit the rearward travel of the operating-sleeve 29 under the urge of its chaser-retracting springs 44-44.

Operation For purposes of description let it be assumed that it is desired to internally thread an object by rotating such object while the collapsing tap is mounted (by means of its shank-portion 16) in the turret of a screw machine or other suitable holder.

Let it further be assumed that the collapsing tap is set or cooked as is shown in Figs. 1 to 8 inclusive. To effect the setting just referred to, the lever-handle 35 will have been manually pushed forwardly to thereby similarly shift the trippingsleeve 3| in the same direction and thus cause the latter to also force the operating-sleeve 29 forwardly until the central portion of the inner rear corner of the plate-like latch-member 58 has been brought into registry with the latchingabutment 6| in the body-member l5 and has moved radially inwardly to engage with the said latching-abutment.

The described forward movement of the operating-sleeve 29 into its latched position will similarly move the coupling-member 59 and hence will also move the chaser-operating plunger 22 forwardly. The forward movement of the chaser-operating plunger will cause the inclined chaser-operating arms 23 to force the chasers 25 radially outwardly into position to cut the desired thread within an object such, for instance, as a pipe-fitting or the like.

After the desired length of thread has been cut by the chasers 25, the collapsing tap may be tripped toradially retire itssaid chasers 25" in one of several modes. 1

For instance, the lever-handle 35 may be manua-l-ly swungrearwardly to thereby slide the tripping-sleeve to which it is pivoted, rearwardly 7 relative w the operating-sleeve Z9;

Still another mode of effecting the rearward,

movement of the tripping-sleeve would be to have'its forward end or an extension thereof, engaged with a suitable abutment which; would halt the forward" travelof the said trippings'leeve,while the remainder of the structure is still advancing duringthe threading operation, to thereby'efiect relative rearward movement of the said tripping-sleeve with respect to the strum ture by which itis carried. The annular groove 35a of the said'tripping-sleeve may also'be-utilized to arrest the forward movement of the trip ping-sl'eeve; as just described.

When the tripping-sleeve Si is moved, rearwardly relative to the operating-sleeve 29, (or equivalently when the forward movement of the tripping-sleeve is halted and the said operatingsleevemovesforwardly relative tothe said tripping sl'eevel', the rearwardly-facing' annular stop-shoulder 32 within the said tripping-sleevewill force the latch-releasing balls 55-65 rearwardly' along the inclined surfaces B 54 of the latch-member 58', thereby forcing the said latchmemberradially outwardly against the tension of the latch-springs 242. As soon as the curved central portion of the upper rear edge of the said latch-member clears the outer corner of the latching-abutment E! of the body-member t5, the operating-sleeve'29- will be free to snap rearwardly under the urge of the chasebretracting springs 4444.

Through the intermediary of the couplingmember 5%, the rearward movement of the operating-sleeve 29" will efiect the similar movement a of the chaser-operating plunger 22; Ehis latter movement will cause the inclined coupling-ribs 24 and the similarly inclined and. inter-engaging coupling-ribs 328 of the chasers 25, to positively move'the said chasers radially inwardly to disengage the thread-cutting teeth 2 thereof from the article which has just been threaded.

The relative rearward movementof the operating-sleeve 29 with respect to the body-member will be effected by the urge of the chaser-retracting springs 64 and will be checked by the engagement of the stop-ball 5"! with the stopabutment formed by the rear end of the longitudinal groove: 80' in the body-member l5. Simi larly, the rearward movement of the trippingsleeve 3i relative to the operating-sleeve 29 upon which it is mounted, will be limited by the. en gagement of the stop-shoulder 52 of the said tripping-sleeve with the stop-screw 33" carried at the rear of the operating-sleeve 29'.

In rare instances where the=thread-cutting teeth- 2"! of thechasers 25 are so tightly engaged with the work-piece being threaded that the chaser" retractingspringse l are: not sufficiently powerful to effect the rearward movement of the operat- 8 V lug-sleeve- 29 and connected parts to thus retract the said chasers; the engagement otthe stopshoulder '32 of the tripping-sleeve; 3t withl the stop-screw 33 will cause the said tripping-sleeve to positively move: the operating-sleeve 29 rearwardly and'thus positively retract the chasers Should it bedesi r'ed to adjust the diameter of the threads to be formed by the thread-cutting teetlizl when the chasers 25 are in their projected positions, the chaser operati ng plunger- 22-and hence thechasers 25--may be adjusted:

by turning the front and rear adjusting-screws 5d and 55 to shift the coupling-member '50 (and;

hence also the plunger 22) in the desired direc-1 ti'on with respect tothe operating-sleeve 29. A' rearward shifting of the coupling-member 50 willcause a lesser-diametered thread to be out, where as an adjustment cf the said coupling-member 50 ina forward direction will: cause a largerdiametered thread to be cut by the chasers- 2-5.

When the chaser-operating plunger '22 is moved rearwardly toefiectthe retirement of the" chasers 25, as previously described, the said plunger does not move sufiicientl-y rearwardl-y to disengage its coupling-ribs 2'4 from' thecoupling-ribs 26 0f the chasers. Thereforawhen it is desired to remove the chasers 25 for-purposes of replacement or other reasons and without] removing the cap IS, the releasing-plunger It may bemoved forwardly, as is indicated in Fig.14.

When the releasing-plunger H1 is moved forwardly as above referred to, its clearance-pocket- 32 will be brought into a position wherein the' stop-bal-l 61 may ride upwardly thereinto and thus clear it of the stop-abutment formed by:

the curved rear endof the longitudinal groove 8% in the body-member l5. When this occurs the operating-sleeve 29 will be forced rearwardly (beyond its normal chaser return-ing position) by the chaser-retracting springs it-4 4 a distance sufficient to fully disengage the chaser-operating arms 23 of the plunger 22 from the chasers 25,

as is shown in Fig. 14'. The said chasers may now be extracted radially fromthe radial guide-slots 2cm the body-member I5.

When as above described, the'operating-sleeve 29 is permitted to move rearwardl'y suihcien-tly' I topermit the removal of the chasers 25-,the rear- Ward movement referred to will be limited by the engagement of the rear edge of the radial coupling-leg as of the coupling-member 50 with the rear wall of the clearance-slot 51 in the body-- member l5. 7 I o The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodirnents are, therefore, to be consideredin all respects as illustrative and not restrictive; and all changes coming within the meaning 'and equivalency range of the appended claims are intended to be embraced therein.

I claim: V 1. A collapsing tap having a plurality of advanceable and; retirable thread-cutting chasers and including in combination: a chaser-carrying member having a plurality of substantially-radial chaser-guides and formed with a forwardlyfacing latchin-g abutment'; a pluralityof thread- 7 stantially-radial latch-receiving passage and with transmitter-guiding means extending in substantial parallelism with the longitudinal axis of the tap; chaser-operating means operatively connectingth said operating-sleeve with the said chasers; spring-means urging the said operatingsleeve rearwardly; a latch-member mounted for movement in a substantially-radial direction in the latch-receiving passage of the said operatingsleeve and engageable with and disengageable from the latching-abutment of the said chasercarrying member, the said latch-member being provided with an inclined releasing-surface sloping forwardly and laterally outwardly away from the longitudinal axis of the tap; a rolling transmitting-member rollable in the transmitterguiding means of the said operating-sleeve in a direction substantially longitudinal of the latter; and a tripping-sleeve axially movable upon the said operating-sleeve and having a rearwardlyfacing abutment engageable with the said transmitting-member to roll the same rearwardly in the transmitter-guiding means of the said operating-sleeve and along the inclined releasingsurface of the said latch-member to force the latter out of engagement with the latching-abutment of the said chaser-carrying member.

2'. A collapsing tap having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chaser-carrying member having a plurality of substantially-radial chaser-guides and formed with a forwardly-facing latching-abutment; a plurality of threadcutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-radial latch-receiving passage and with two laterally-spacecl-apart transmitter-guiding means both extending insubstantial parallelism with the longitudinal axis of the tap; chaseroperating means operatively connecting the said operating-sleeve with the said chasers; springmeans urging the said operating-sleeve rearwardly; a latch-member mounted for movement in a substantially-radial direction in the latchreceiving passage of the said operating sleeve and engageable with and disengageable from the latching-abutment of the said chaser-carrying member, the said latch-member being provided with two laterally-spaced-apart inclined releasing surfaces each sloping forwardly and laterally outwardly away from the longitudinal axis of the tap and respectively registering with the transmitter-guiding means in the said chasercarrying member; two rolling transmitting-members respectively movable in the transmitterguiding means of the said operating-sleeve in a direction substantially longitudinal of the latter; and a tripping-sleeve axially movable upon the said operating-sleeve and having rearwardlyfacing abutments respectively engageable with the two said transmitting-members to roll the same rearwardly in their complemental transmitter-guiding means of the said operating-sleeve and respectively along the inclined releasing surfaces of the said latch-member to force the latter out of engagement with the latching-abutmen of the said chaser-carrying member.

3. A. collapsing tap having a plurality of advanceahle and retirable thread-cutting ehasers and including in combination: a chaser-carrying member having a plurality of substantially-radial chaser-guides and formed with a forwardly-facing latching-abutment; a plurality of threadcutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-radial latch-receiving passage and with a ball-guiding passage extending in substantial parallelism with the longitudinal axis of the tap; chaser-operating means operatively connecting the said operating-sleeve with the said chasers; spring-means urging the said operating-sleeve rearwardly; a latch-member mounted for movement in a substantially-radial direction in the latch-receiving passage of the said operatingsleeve and engageable with and disengageable from the latching-abutment of the said chasercarrying member, the said latch-member being provided with an inclined releasing-surface sloping forwardly and laterally outwardly away from the longitudinal axis of the tap; a transmittingba'll rollable in the ball-guiding passage in the said chaser-operating sleeve in a direction substantially longitudinal of the latter; and a tripping-sleeve axially movable upon the said operating-sleeve and having a rearwardly-facing abutment engageable with the said transmittingball to roll the same rearwardly in the ballguiding passage in the said operating-sleeve-and along the inclined releasing-surface of the" said latch-member to force the latter out of engagement with the latching-abutment of the said chaser-carrying member.

4. A collapsing tap having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chaser-carrying member having a plurality of substantially-radial chaser-guides and formed with a forwardly-facing latching-abutment; a plurality of threadcutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-radial latch-receiving passage and with two laterally-spaced-apart ball-guiding passages both extending in substantial parallelism with the longitudinal axis of the tap; chaser-operating means operatively connecting the said operatinging-sleeve with the said chasers; spring-means urging the said operating-sleeve rearwardly; a

latch-member mounted for movement in a substantially-radial direction in the latch-receivin passage of the said operating-sleeve and engage able with and disengageable from the latchingabutment of the said chaser-carrying member, the said latch-member being provided with two laterally-spaced-apart inclined releasing-surfaces each sloping forwardly and laterally outwardly away from the longitudinal axis of the tap and respectively registering with the ball-guiding passages in the said chaser-carrying member; two transmitting-balls respectively reliable in the ball-guiding passages in the said chaser-operating sleeve in a direction substantially longitudinal of the latter; and a tripping-sleeve axially movable upon the said operating-sleeve and having rearwardly-facing abutments respectively engageable with the said transmitting-balls to roll thesame rearwardly in the ball-guiding passages in the said operating-sleeve and along the inclined releasing-surface of the said latch-member to force the latter out of engagement with the latching-abutment of the said chaser-carrying member.

'11 "iccllapsing tap having a nllurality'ci ail-- vaneeable and retirable thread-cutti g chasers andiincluding in combination: a chaser-carryin member having a plurality of substantially r dial chasereguides and having a longitudinal passage in its interio the said chaser-ca ry ng member being :formed with .a clearance-slot leading out- Ward'ly from the said longitudinal passage to the outer surface of the member; a "plurality of thread-cuttin chasers carried by the saidch-asercarrying member s and :movable substantially radially in the chaseruides thereof; a chaseroperating plunger movable in the longitudinal passag in the Said chaser-carrying member and operatively connected to the said chasers to a vance and retire the same; an .operatlngesleeve mounted for axial movement upon the said Qhaser carrying member and formed witha longitudinal cylindrical guide passage communicating laterally with the clearance-slet in the said chaser-carrying member; a coupling-member having a cylindrical portion closely fitting and movable in the longitudin l guide passage in the said "o erating-sleeve and having a coupling-leg extending laterally inwardly through the clearlance-slot in the said chaser-carrying member and .cperatively connected to the said chaseroperating plunger; adjusting-means carried by the said operatin -sleeve and en ing the said cmxpl-m'g-member to shift longitudinally relative to the operating-sleeve and hence also correspondingly shift the said chaser-operating plunger; spring-means urging the said operating,

leeve in an axial direction and latch-means releasably couplin the said operating-sleeve to the said chaser-carrying member to releasahly hold the former against axial movement under the urge of the said spring'meansthe said latchmeans being independent of and unaffected by theiadiustment of the said coupling-member.

6. A collapsing tap having a plurality of adyaneeable and retirable't'hread-cutting chasers vance and retire the same; anioperatl-ng-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a longitudinal guide passage communicating laterally the clearance-slot in the said chasercarryi-ngmember; a 'T-shaped coup-ling -member havmea' body closely fitting and movable in the 1ong-izdudinal guide passage in the said opratingsleeve and having a coupling-leg. intermediate its opposite ends and extending laterally inwardly 'throu h the. clearance-slot in the said chasercarryin member the said collpling leg being operatively connected to the said chaser-operatin plunger; adlustingemeans carried by the said operating-sleeve and engaging the said T-shap.ed coupling-member to shift it longitudinally relafive-1'10 the operating-sleeve'and hence also correspondingly shift the said chaser-operating plunger; spring-means urging the said operat 7 ing-sleeve in an axial direction; and latch-means releasably ccupling'the said operating-sleeve-to the said chaser-carrying'member to releasably hold the former against axial movement under the urge of the said spring-means the saidlatch means being independent of and unaffected by the adjustment of the said T-shaped couplingmember.

'7. A collapsing tap having a plurality of advanceable and retir-able thread-cutting Chasers and including in combination: a chaser-carrying member having a'plurality of substantially-radial chaser-guides and having longitudinal passage in its interior, the said chaser-carrying member being formed with a clearance-slot leading out- Wardly ,from the said longitudinal passage tothe outer surface of the member; plurality of thread-cutting Chasers carried by the said chasercarrying memberand movable substantially ra dially in the chaser-guides thereof; a chaseroperati-ng plunger movable; in the longitudinal passage in the said chaser-carrying member and operatively connected to the said chasers to advance and retirethe same; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a longitudinal cylindrical guide'passage communicating laterally with the clearance-slot in the said chaser-carrying member; a coupling-member having a cylindrical body closely fitting and movable in the longitudinal guide passage in the said operating-sleeve and having a coup1lng-leg extending laterally inwardly through the clearance-slot in the said chaser-carryingmember and operativeiy connected to the said chaser opeliating'plunger; a pair of adjusting-screws carried by the said operating-sleeve and respecti-vely engaging opposite ends of the body of the said coupling-member to shift it longitudinally relative to the operating-sleeve and hence also correspondingly shift the said chaser-operating plunger; spring-means urging the said operatsingeslieeve in an axialdirecti-on; and latch-means I releasably'coupling the said operating-sleeve to i the said chaser-carrying member to releasably hold the former against axial movement under the urge of the said spring-means the said latchmeans being independent of and'unailected' by the. adjustment of the said coupling-member;

8. A collapsing tap having a plurality of advanceable and. retirable thread-cutting chasers and including in combination: a, chaser-carrying 7 member having a plurality of substantially-radial chaser-guides and having a longitudinal passage in its interior the said chaser-carrying member;

being formed with a clearance-slot leading outwardly from the said longitudinal passage to the outer surface of the member; a plurality of threadecutting chasers 'carried by the said chaser-carrying member-and movable substantially radially in the chaser-guides thereof j; a chaser-operating plunger movable in the longitudinal passage in the said chaser-carrying memher and operatively connected to the said chasers to advance and retire the same; an operating ,sleeve mounted for axial movement upon the said chaser-carrying member and'formed With a 1011- j gitudinal passage communicating laterally with the clearance-slot in the said vchaser-carrying member; a T-shaped coupling-member movable in the longitudinal passage in the said operatingsleeve and having a, coupling-leg intermediate its opposite ends and extending laterally inwardly through the clearance-slot in the said chasercarrying member the said coupling-leg being operatively connected to the said chaser-operating 13 plunger; a pair of adjusting-screws carried by the said operating-sleeve and respectively engaging opposite end portions of the said T-shaped coupling-member to shift it longitudinally relative to the operating-sleeve and hence also correspondingly shift the said chaser-operating plunger; spring-means urging the said operatingsleeve in an axial direction; and latch-means releasably coupling the said operating-sleeve to the said chaser-carrying member to releasably hold the former against axial movement under the urge of the said spring-means the said latchmeans being independent of and unaffected by the adjustment of the said Tshaped coupling member.

9. A thread-cutting device having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides and provided at its periphery with a stop-abutment; a plurality of thread-cutting chasers carried by the said chasercarrying member and movable substantially radially in the chaser-guides thereof; an operating sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantiallyelongitudinal plunger-receiving passage located adjacent the stop-abutment of the said chaser-carrying member but spaced out wardly therefrom, the said operating-sleeve also being formed with a lateral guide-passage extending between. the inner periphery of the operating sleeve and the plunger-receiving passage therein; a stop-member mounted for movement in the la eral guide-passage in the said operating-sleeve and engageable with the stop-abutment of the chaser-carrying member to limit the movement of the operating-sleeve; a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and having a portion normally overlying the outer portion of the said stop-member to releasabl y hold the same against outward movement and compel the stop-member to engage with the said stop-abutment to limit the travel of the operating-sleeve, the said releasing-plunger being provided with a clearance-portion movable into registry with the said stop-member to permit the latterto move outwardly clear of the stop-abutment of the chaser-carrying member; spring-means urging the said operating-sleeve in an axial direction with respect to the said chaser-carrying member; and releasable latch-means releasably restraining the said operating-member against axial movement under the urge of the said springmeans.

10. A thread-cutting device having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides and provided at its periphery with a, stop-abutment; a plurality of thread-cutting chasers carried by the said chasercarrying member and movable substantially ra, dially in the chaser-guides thereof; an operatingsleeve mounted for axial movement upon the said chaser-carrying member and formed with a sub stantial-Iy-longitudinal plunger-receiving passage located adjacent the stop-abutment of the said chaser-carrying member but spaced outwardly therefrom, the said operating-sleeve also being formed with a lateral guide-passage extending between the inner periphery of the operatingsleeve and the plunger-receiving passage therein; a stop-ball mounted for movement in the lateral guide-passage in the said operating-sleeve and engageable with the stop-abutment of the chasercarrying member to limit the movement of the operating-sleeve; a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and having a portion normally overlying the outer portion of the said stop-ball to releasably hold the same against outward movement and compel the stop-ball to engage with the said stop-abutment to limit the travel of the operating-sleeve, the said releasingpiunger being provided with a clearance-portion movable into registry with the said stop-ball to permit the latter to move outwardly clear of the stop-abutment of the chaser-carrying member; spring-means urging the said operating-sleeve in an axial direction with respect to the said chasercarrying member; and releasable latch-means reloasabiy restraining the said operating-member against axial movement under the urge of the said spring-means.

11. A thread-cutting device having a, plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides and provided at its periphery with a stop-abutment; a plurality of thread-cutting chasers carried by the said chasercarrying member and movable substantially radially in the chaser guides thereof; an operating. sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-longitudinal plunger-receiving passage located adjacent the stop-abutment of the said chaser-carrying member but spaced outwardly therefrom, the said operating-sleeve also being formed with a lateral guide-passage extending between the inner periphery of the operating-sleeve and the plunger-receiving passage therein; a stop-member mounted for movement in the lateral guide-passage in the said operating-sleeve and engageable with the stop-abutment of the chaser-carrying member to limit the movement of the operating-sleeve; a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and hav ing a portion normally overlying the outer portion of the said stop-member to releasably hold the same against outward movement and compel'the stop-member to engage with the said stop--abutment to limit the travel of the operating-sleeve, the said releasing-plunger being provided with a clearance-portion movable into registry with the said stop-member to permit the latter to move outwardly clear of the stop-abutment of the chaser-carrying member; spring-means urging the said releasing-plunger in. a direction to yieldingly hold its clearance-portion out of registry with the said stop-member; spring-means urging the said operating sleeve in an axial direction with respect to the said chaser carrying member; and releasable latch-means releasably restraining the said operatingunember against axial movement under the urge of the said spring means.

12. A thread-cutting device having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radialchaser-guides and provided at its periphery with a stop-abutment; a plurality of thread-cutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guides thereof. an operating-sleeve mounted for axial movement upon aesaeae the said chaser-carrying member and formed with a substantially-longitudinal plunger-receiving passage located adjacent the stop-abutment of the said chaser-carrying member but spaced outwardly therefrom, the said operating-sleeve also being formed with a lateralguide-passage extending between the inner periphery of the operating-sleeve and the plunger-receiving passage therein; a stop-ball mounted for movement in' thelateral guide-passage in the said operating-sleeve and engageable with the stop-abutment of the chaser-carrying member to limit the movement of the operating-sleeve; Va releasingplunger'mountedfor reciprocation in the plunger-r'eceiving passage of the said operating-sleeve and having a portion normally overlying the outer portion of the said stop-ball to releasably hold the same against outward movement and compel the stop-ball to engage with the said stop-abutment to limit the travel of the operating-sleeve, the said releasing-plunger being provided with a clearance-portion movable into registry with the said stop-ball to permit the latter to move outwardly clear of the stop-abutment of thechaser-carrying member; spring-means urging the said releasing-plunger in a direction to yieldingly hold its clearance-portion out of registry with the said stop-ball; spring-means urging the said operating-sleeve in an axial direction with respect to the said chaser-carrying member; and releasable latch-means releasably restraining the said operating-member against axial-movement under'ethe urge of said springmeans.

13. A thread-cuttingdevice having a plurality of V advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides and formed in its periphery with a substantially-longitudinal groove having a forwardly-facing stop-abutment at its rear; a plurality of thread-cutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaserguides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-longitudinal plunger-receiving passage located adja-'- cent the longitudinal groove in the periphery of the said chaser-carrying member but spaced outwardly therefrom, the said operating-sleeve 16 to ride upon the periphery of the saidchasercarrying member.

14. A thread-cutting: device having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides andformed in its periphery with asubstantially-longitudinal groove having a'forwardly-facing stop-abutment at its rear; a plurality of thread-cutting chasers carried by the said chaser-carrying member and a movable substantially radially in the chaseralso being formed with a lateral guide-passage 7 extending between the longitudinal groove in the said chaser-carrying member and the plungerreceiving passage in the operating-sleeve; a stopmembermounted for movement in the lateral guide-passage in the said operating-sleeve and engageable with the said stop-abutment to limit the movement of the operating-sleeve with respect to the chaser-carrying member, the said stop-member having a dimension in a radial direction exceeding the distance between the pelriphery of the said chaser-carrying member and the plunger-receiving passage in the said operating-sleeve; and a-releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and formed witha clearance-recess opening toward the periphery of the said chaser-carrying, member, the said clearance-recess having a depth sufiicient to accommodate the said stop-member when the releasing-plunger is moved longitudinally to register its said clearance-recess with the said stopmember and when the latter is moved outwardly guides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-longitudinal plunger-receiving passage located adjae cent the longitudinal groove in the periphery of the said chaser-carrying member but spaced outwardly therefrom, the said operating-sleev also being formed with a lateral guide-passage extending between the longitudinal groove in the said chaser-carrying member and the plungerreceiving passage in the operating-sleeve; a stopball mounted for movement in the lateral guidepassage in the said operating-sleeve and engageable with the said stop-abutment to limit the movement of the operating-sleeve with respect to the chaser-carrying member, the said stop-ball having adiameter exceeding the distance between the periphery of the said chaser-carrying member and the plunger-receiving passage in the said operating-sleeve; and a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and formed with a clearance-recess opening toward the periphery of the said chaser-carrying member, the said clearance-recess having a depth sufiicient to accommodate the said stop-ball when the releasing-plunger ismoved longitudinally to register its said clearance-recess with the said stop ball and when the latter ismoved outwardly to ride upon the periphery of the said chaser-car- V rying member. V

15'. A thread-cutting device having aplurality of advanceable and retirable thread-cutting chasers and including in combination: a chaser-carrying member having a plurality of substantiallyradial chaser-guides and formed in its periphery with a substantially-longitudinal groove having a forwardly-facing stop-abutment at its rear; a plurality of thread-cutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guidesithereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-longitudinal plungerreceiving passage located adjacent the longitudinal groove in the periphery of the said chasercarrying member but spaced outwardly therefrom, the said operating-sleeve'also being formed with a lateral guide-passage extending between the longitudinal groove in the said chaser-carrying member and the plunger-receiving passage in the operating-sleeve; a stop-member mounted for movement in the lateral guide-passage in the said operating-sleeve and engageable with the said stop abutment to limit th movement of the operating-sleeve with respect to the chasercarrying member, the said stop-member having 7 a dimension in a radial direction exceeding the 7 distance between the periphery of the said chaser-carrying member and the plunger-"receivin-g passage in the said operating-sleeve; a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operatingsleeve and formed with a clearance-recess opening toward the periphery of the said chaser-carrying member, the said clearance-recess having a depth sufiicient to accommodate the said stopmember when the releasing-plunger is moved longitudinally to register its said clearance-recess with the said stop-member and when the latter is moved outwardly to ride upon the periphery of the said chaser-carrying member; and springmeans urging the said releasing-plunger in a direction to yieldingly hold its clearance-recess out of registry with the said stop-member.

16. A thread-cutting device having a plurality of advanceable and retirable thread-cutting chasers and including in combination: a chasercarrying member having a plurality of substantially-radial chaser-guides and formed in its periphery with a substantially-longitudinal groove having a forwardly-facing stop-abutment at its rear; a plurality of thread-cutting chasers carried by the said chaser-carrying member and movable substantially radially in the chaser-guides thereof; an operating-sleeve mounted for axial movement upon the said chaser-carrying member and formed with a substantially-longitudinal plungerreceiving passage located adjacent the longitudinal groove in the periphery of the said chasercarrying member but spaced outwardly therefrom, the said operating-sleeve also being formed with a lateral guide-passage extending between the longitudinal groove in the said chaser-carrying member and the plunger-receiving passage in the operating-sleeve; a stop-ball mounted for 18 movement in the lateral guide-passage in the said operating-sleeve and engageable with the said stop-abutment to limit the movement of the operating-sleeve with respect to the chasercarrying member, the said stop-ball having a diameter exceeding the distance between the periphery of the said chaser-carrying member and the plunger-receiving passage in the said operating-sleeve; a releasing-plunger mounted for reciprocation in the plunger-receiving passage of the said operating-sleeve and formedwith a clearance-recess opening toward the periphery of the said chaser-carrying member, the said clearance-recess having a depth sufficient to accommodate the said stop-ball when th releasingplunger is moved longitudinally to register its said clearance-recess with the said stop-ball and when the latter is moved outwardly to ride upon the periphery of the said chaser-carrying member; and spring-means urging the said releasingplunger in a direction to yieldingly hold its clearance-recess out of registry with the said stopball.

ROYCE M. STRICKLAND.

REFERENCES CITED UNITED STATES PATENTS Name Date Leidy Nov, 20, 1900 Number 

